private Employee GetEmployeeForLoggedUser()
        {
            var hasher = new Sha256StringHasher();
            var existingUser = _employeeRepository.Find(hasher.Hash(UserName));

            return existingUser;
        }
        private void GetEmployeeAndLoadNextView()
        {
            var employee = GetEmployeeForLoggedUser();

            if (employee == null)
            {   var hasher = new Sha256StringHasher();
                var employeeForNewUser = new Employee {Login = hasher.Hash(UserName)};
                ChangeUtility(new CreateEmployeeViewModel(employeeForNewUser, _employeeRepository, MainViewModel));
            }
            else
            {
                LoadViewModel(new HolidayCalendarViewModel(employee, _employeeRepository));
                Close();
            }
        }